In the lesson on agribusiness, the instructor, Derk Muscat, discussed important topics related to aquaculture and emphasized the need for proper health and safety practices. They outlined the importance of testing the water quality and the implications of ensuring that fish are healthy for farming purposes. The teacher also encouraged students to start their practical work at the base level to ensure a thorough understanding of the processes involved. Overall, the session aimed to engage students in hands-on learning while highlighting critical safety measures in aquaculture.